150 SOUTH INDIAN GRASSES 



20. Ischaemum, L. 



The grasses of this genus are either annuals or perennials. 

 The inflorescence consists of spikes, solitary, digitate or fascicled, 

 articulate and fragile ; the joints of the floral axis and the pedicels 

 of the pedicelled spikelets are trigonous and hollowed ventrally. 

 Spikelets are binate, one sessile and one pedicelled; the pedicelled 

 spikelets are dissimilar from the sessile and both usually 2- 

 flowered. The sessile spikelets have four glumes. The first 

 glume is coriaceous, oblong or lanceolate, convex more or less, 

 marginally winged above the middle, truncate or two-cuspidate 

 at the apex and awnless. The second glume is as long as the first, 

 coriaceous, concave, acute or obtuse, awned or not. The third 

 glume is hyaline, deeply cleft into two lobes with an awn in the 

 cleft, and 3-nerved, paleate ; palea is linear-lanceolate enclosing 

 either stamens and ovary or ovary alone. Lodicules are cuneate 

 or quadrate. 



Key to Species. 



Racemes two or three; the first glume of the sessile spikelet 

 dorsally fiat, not channelled or depressed along the middle line. 



Margin of the first glume of the sessile spikelet incurved 

 narrowly from the base to the apex. 

 First glume of sessile spikelets with 1 _ T ... 



nodulose margins. [ l L anstatum - 



First glume of sessile spikelets closely \ „ T 



transversely ribbed. / 2 " L ™£OSum. 



First glume of the sessile spikelet"! 



translucent, bicuspidate at the tip and > 3. I. pilosum. 

 with smooth margins. 

 Margin of the first glume of the sessile spikelet broadly 

 incurved from below the middle. 



First glume of the sessile spikelet with \ r •,-. 

 smooth margins, callus bearded. i ^' " C1 iar ' 



Raceme solitary; the first glume of the sessile] 



spikelet deeply grooved at the back along the > 5. I. laxum. 

 middle line. 



